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Endoxifen Article
Endoxifen
Endoxifen, chemically designated as 4-hydroxy-N-desmethyltamoxifen, is a synthetic triphenylethylene derivative and the primary active metabolite of the pioneering selective estrogen receptor modulator (SERM) tamoxifen. In classical endocrine research models, parent tamoxifen requires extensive hepatic bioactivation via the polymorphic cytochrome P450 2D6 (CYP2D6) enzyme pathway to achieve full potency.
Endoxifen completely bypasses this initial enzymatic step. Because it is supplied in its fully bioavailable, post-metabolic configuration, it acts as a direct, high-affinity ligand at both estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ) sites. This makes it an essential reference standard for evaluating hormone-responsive cellular matrices without the confounding experimental variables introduced by genetic CYP450 metabolic variations.
Structural Elements of Interest: Endoxifen retains the characteristic core triphenylethylene framework shared across the tamoxifen family, but features two critical modifications: an added hydroxyl (-OH) group at the para-position of one phenyl ring and the removal of a methyl group from the tertiary amine side chain (N-desmethylation). These optimized functional groups significantly alter its spatial alignment, allowing it to bind to the estrogen receptor pocket with up to 100-fold greater affinity than parent tamoxifen.
Technical Specifications
| Property | Specification |
|---|---|
| Product Name | Endoxifen (Free Base) |
| Chemical Name | 4-hydroxy-N-desmethyltamoxifen |
| Available Salt Form | Endoxifen Citrate |
| Molecular Formula | C₂₅H₂₇NO₂ |
| Molecular Weight | 373.49 g/mol (Free Base) |
| Chemical Class | Triphenylethylene Derivative / High-Affinity SERM |
| Physical Appearance | Off-white to pale crystalline solid / fine powder |
| Solubility Profile | Soluble in organic solvents (DMSO, Ethanol, DMF) |
| Solution Base | PEG400, Ethanol |
Research Applications & Mechanism of Interest
The utility of Endoxifen within reproductive biology, oncology cell lines, and molecular endocrinology stems from its strong and predictable competitive target engagement.
Primary fields of preclinical and in vitro laboratory study include:
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Estrogen Receptor Signaling Kinetics: Investigating high-affinity competitive binding profiles at ERα and ERβ receptors to map the comparative displacement rates of endogenous estradiol.
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Transcriptional Inhibition Models: Tracking downstream signaling events where Endoxifen blocks estrogen-mediated gene transcription, suppressing the expression of estrogen-responsive target proteins.
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Tissue-Selective Agonist/Antagonist Profiling: Evaluating the complex structural behavior of coregulator recruitment to observe how the molecule alternates between estrogenic and anti-estrogenic profiles across varying tissue matrices.
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CYP-Independent Experimental Matrices: Serving as a definitive control in hormone-responsive cell line assays (such as MCF-7) to isolate pure SERM activity without the baseline interference of mixed metabolic conversion rates.
Storage & Handling Guidelines
Store at controlled room temperature. Keep tightly closed. Liquid formats: do not refrigerate or freeze. Cold storage may cause the solution to cloud or precipitate. If this occurs, return to room temperature and mix until clear.
Storage guidance is a house recommendation. Analytical documentation is per-lot release testing.
Related Research Compounds
Analytical Documentation
Purity, identity, and composition vary by manufacturing lot. Kimera Chems does not publish a single fixed purity figure for this item; refer to the batch-specific Certificate of Analysis (COA) issued for the lot received, which reflects third-party analytical testing for that lot. Contact us if a COA for your lot is required.
Research Use Only Disclaimer: This product is developed, synthesized, and distributed strictly as a Research Use Only (RUO) laboratory reference chemical intended exclusively for non-clinical analytical and scientific investigation. It is not an FDA-approved medication, drug formulation, clinical therapeutic, or dietary supplement, and is strictly prohibited for direct human or veterinary use. Kimera Chems supplies these high-grade chemical reference standards solely to accredited institutional laboratories and qualified scientific investigators.
